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and to the absolute entropies, have been calculated for the seven hydrocarbons a t their respective normal boiling points. Comparisons with other data in the literature have been made. A discussion of the correlation of the gas imperfection effects with other molecular quantities has been given, and it has been shown that the numerical magnitude of the normal boiling point may, to a certain extent, serve as an index to the imperfections. Professor E. B. Wilson, Jr., has kindly made several suggestions concerning the preparation of this paper. REFERENCES (1) COFFINAND MAASS:Trans. Roy. SOC.Can. !21,33(1927). (2) COFFINAND MAASS:J. Am. Chem. SOC.60, 1427 (1928). (3) CRAWFORD AND RICE: J. Chem. Phys. 7, 437 (1939). (4) EGANAND KEMP: J. Am. Chem. SOC. 69, 1264 (1937). (5) EUCKEN AND PARTS:Z. physik. Chem. BSO, 184 (1933). (6) GIAUQUE AND WIEBE: J. Am. Chem. SOC.60, 101 (1928). (7) GROSSEAND LINN: J. Am. Chem. Sac. 61,751 (1939). (8)International Critical Tables, Vol. 111, p. 230. McGraw-Hill Book Company, Inc., New York (1928). (9) KISTIAKOWSKY AND RICE: J. Chem. Phys. 8, 610,618 (1940). (10)LAMBAND ROPER:J. Am. Chem. SOC.62,806 (1940). (11) LEWISAND RANDALL: Thermodynamics, pp. 192-8. McGraw-Hill Book Company, Inc., New York (1923). (12) LINNETTAND AVERY: J. Chem. Phys. 6, 686 (1938). (13) MASSONAND DOLLEY:Proc. Roy. SOC.(London) AlOS, 524 (1923). (14) PALLAND hfaass: Can. J. Research 14B,96 (1936). (15) POWELL AND GIAUQUE: J. Am. Chem. SOC.61, 2366 (1939). (16) ROPER:J. Phys. Chem. 44,835 (1940). (17) ROPER:J. Chem. Phys. 8, 290 (1940).
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T H E CATALYTIC -4CTIOX OF NATURAL MINERAL WATERS GEORG CRONHEIM ??ew York State Research Institute, Saratoga S p a , Saratoga Springs, New York Received March 81, 1940
Since R. G l h a r d (7), in 1911, discovered the “catalatic” and “peroxidatic” properties of the mineral waters of Vichy (France), a whole series of papers have been published about them. The work of Baudisch and Davidson (2) on the mineral waters of Saratoga Springs, New York, in 1927, gave a new impetus to these investigations. The assumption by these authors that the iron in these waters exists in an “active,” probably
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complex form was the cause of lively discussion (Fresenius, Eichler, and Griinhut (4)) Simon and Kotzschau (15), and others). As the most important argument against the “active” iron, Fresenius alleged that he was able by “suitable treatment’’ (heating of the solution during the passing of carbon dioxide) to produce an artificial mineral water of the same composition as the U’iesbadener Kochbrunnen and also of the same catalytic property. Similar observations were made by Lang and coworkers (13). They found in their experiments with salt solutions that the carbon dioxide developed by chemical reaction in the solution possesses a higher “efficiency’J than carbon dioxide passed through the solution, and they think that the carbon dioxide in natural mineral waters possesses this efficiency in an especially high degree. These questions will not be discussed in more detail at this time, but the following point should be emphasized: the fact t>hatit is possible t o produce an artificial mineral water with the same catalytic properties as natural water does not prove that the iron of these waters iq not in any “active” form. On the contrary, the above-mentioned observations demonstrate That the catalytic activity depends not only on the quantity of the dissolved constituents but also on the contlitiori to which they could be brought by “suitahle treatment.” Further proof of this point is given by table 1 , which contains data for some mincral water? known to have considerable catalytic activity. “Considerable catalj-tie activity” refers t o c a s w where thc destruction of hydrogen peroxide reaches a noticeable dcgrce even after GO min. Table 1 also lists the ferrous-ion, bicarbonateionj sodium bicarbonate, and free carbon dioxide content of these waters. From thc table it is clear that the catalytic activity is not directly dependent on the amount of iron present in t h e mineral water. The investigated waters of Carlsbad and Vichy ‘haw low iron content and very strong catalytic activity. On the contrary, I
